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Search: id:A162700
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| A162700 |
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Numbers n which are concatenations n=x//y such y^2-x^2 = n. |
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+0
2
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| 48, 3468, 10101, 16128, 34188, 140400, 190476, 216513, 300625, 334668, 416768, 484848, 530901
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Cases with leading zeros of y are not considered.
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EXAMPLE
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48=4//8=8^2-4^2. 10101=10//101 = 101^2-10^2. 16128=16//128= 128^2-16^2.
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MAPLE
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Lton := proc(L) add( op(i, L)*10^(i-1), i=1..nops(L)) ; end:
for n from 10 do dgs := convert(n, base, 10) ; for spli from 1 to nops(dgs)-1 do ydgs := [op(1..spli, dgs)] ; xdgs := [op(spli+1..nops(dgs), dgs)] ; if op(-1, ydgs) <> 0 then x := Lton(xdgs) ; y := Lton(ydgs) ; if y^2-x^2 = n then print(n) ; fi; fi; od: od: # R. J. Mathar, Jul 16 2009
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CROSSREFS
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Sequence in context: A009992 A042105 A079240 this_sequence A027567 A033475 A053060
Adjacent sequences: A162697 A162698 A162699 this_sequence A162701 A162702 A162703
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KEYWORD
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nonn,base,more
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AUTHOR
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Claudio L Meller (claudiomeller(AT)gmail.com), Jul 11 2009
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EXTENSIONS
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keyword:base added, definition rephrased, values sorted by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 16 2009
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